diff options
Diffstat (limited to 'arch/ia64/mm/tlb.c')
-rw-r--r-- | arch/ia64/mm/tlb.c | 562 |
1 files changed, 562 insertions, 0 deletions
diff --git a/arch/ia64/mm/tlb.c b/arch/ia64/mm/tlb.c new file mode 100644 index 000000000..acf10eb9d --- /dev/null +++ b/arch/ia64/mm/tlb.c @@ -0,0 +1,562 @@ +/* + * TLB support routines. + * + * Copyright (C) 1998-2001, 2003 Hewlett-Packard Co + * David Mosberger-Tang <davidm@hpl.hp.com> + * + * 08/02/00 A. Mallick <asit.k.mallick@intel.com> + * Modified RID allocation for SMP + * Goutham Rao <goutham.rao@intel.com> + * IPI based ptc implementation and A-step IPI implementation. + * Rohit Seth <rohit.seth@intel.com> + * Ken Chen <kenneth.w.chen@intel.com> + * Christophe de Dinechin <ddd@hp.com>: Avoid ptc.e on memory allocation + * Copyright (C) 2007 Intel Corp + * Fenghua Yu <fenghua.yu@intel.com> + * Add multiple ptc.g/ptc.ga instruction support in global tlb purge. + */ +#include <linux/module.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/smp.h> +#include <linux/mm.h> +#include <linux/bootmem.h> +#include <linux/slab.h> + +#include <asm/delay.h> +#include <asm/mmu_context.h> +#include <asm/pgalloc.h> +#include <asm/pal.h> +#include <asm/tlbflush.h> +#include <asm/dma.h> +#include <asm/processor.h> +#include <asm/sal.h> +#include <asm/tlb.h> + +static struct { + u64 mask; /* mask of supported purge page-sizes */ + unsigned long max_bits; /* log2 of largest supported purge page-size */ +} purge; + +struct ia64_ctx ia64_ctx = { + .lock = __SPIN_LOCK_UNLOCKED(ia64_ctx.lock), + .next = 1, + .max_ctx = ~0U +}; + +DEFINE_PER_CPU(u8, ia64_need_tlb_flush); +DEFINE_PER_CPU(u8, ia64_tr_num); /*Number of TR slots in current processor*/ +DEFINE_PER_CPU(u8, ia64_tr_used); /*Max Slot number used by kernel*/ + +struct ia64_tr_entry *ia64_idtrs[NR_CPUS]; + +/* + * Initializes the ia64_ctx.bitmap array based on max_ctx+1. + * Called after cpu_init() has setup ia64_ctx.max_ctx based on + * maximum RID that is supported by boot CPU. + */ +void __init +mmu_context_init (void) +{ + ia64_ctx.bitmap = alloc_bootmem((ia64_ctx.max_ctx+1)>>3); + ia64_ctx.flushmap = alloc_bootmem((ia64_ctx.max_ctx+1)>>3); +} + +/* + * Acquire the ia64_ctx.lock before calling this function! + */ +void +wrap_mmu_context (struct mm_struct *mm) +{ + int i, cpu; + unsigned long flush_bit; + + for (i=0; i <= ia64_ctx.max_ctx / BITS_PER_LONG; i++) { + flush_bit = xchg(&ia64_ctx.flushmap[i], 0); + ia64_ctx.bitmap[i] ^= flush_bit; + } + + /* use offset at 300 to skip daemons */ + ia64_ctx.next = find_next_zero_bit(ia64_ctx.bitmap, + ia64_ctx.max_ctx, 300); + ia64_ctx.limit = find_next_bit(ia64_ctx.bitmap, + ia64_ctx.max_ctx, ia64_ctx.next); + + /* + * can't call flush_tlb_all() here because of race condition + * with O(1) scheduler [EF] + */ + cpu = get_cpu(); /* prevent preemption/migration */ + for_each_online_cpu(i) + if (i != cpu) + per_cpu(ia64_need_tlb_flush, i) = 1; + put_cpu(); + local_flush_tlb_all(); +} + +/* + * Implement "spinaphores" ... like counting semaphores, but they + * spin instead of sleeping. If there are ever any other users for + * this primitive it can be moved up to a spinaphore.h header. + */ +struct spinaphore { + unsigned long ticket; + unsigned long serve; +}; + +static inline void spinaphore_init(struct spinaphore *ss, int val) +{ + ss->ticket = 0; + ss->serve = val; +} + +static inline void down_spin(struct spinaphore *ss) +{ + unsigned long t = ia64_fetchadd(1, &ss->ticket, acq), serve; + + if (time_before(t, ss->serve)) + return; + + ia64_invala(); + + for (;;) { + asm volatile ("ld8.c.nc %0=[%1]" : "=r"(serve) : "r"(&ss->serve) : "memory"); + if (time_before(t, serve)) + return; + cpu_relax(); + } +} + +static inline void up_spin(struct spinaphore *ss) +{ + ia64_fetchadd(1, &ss->serve, rel); +} + +static struct spinaphore ptcg_sem; +static u16 nptcg = 1; +static int need_ptcg_sem = 1; +static int toolatetochangeptcgsem = 0; + +/* + * Kernel parameter "nptcg=" overrides max number of concurrent global TLB + * purges which is reported from either PAL or SAL PALO. + * + * We don't have sanity checking for nptcg value. It's the user's responsibility + * for valid nptcg value on the platform. Otherwise, kernel may hang in some + * cases. + */ +static int __init +set_nptcg(char *str) +{ + int value = 0; + + get_option(&str, &value); + setup_ptcg_sem(value, NPTCG_FROM_KERNEL_PARAMETER); + + return 1; +} + +__setup("nptcg=", set_nptcg); + +/* + * Maximum number of simultaneous ptc.g purges in the system can + * be defined by PAL_VM_SUMMARY (in which case we should take + * the smallest value for any cpu in the system) or by the PAL + * override table (in which case we should ignore the value from + * PAL_VM_SUMMARY). + * + * Kernel parameter "nptcg=" overrides maximum number of simultanesous ptc.g + * purges defined in either PAL_VM_SUMMARY or PAL override table. In this case, + * we should ignore the value from either PAL_VM_SUMMARY or PAL override table. + * + * Complicating the logic here is the fact that num_possible_cpus() + * isn't fully setup until we start bringing cpus online. + */ +void +setup_ptcg_sem(int max_purges, int nptcg_from) +{ + static int kp_override; + static int palo_override; + static int firstcpu = 1; + + if (toolatetochangeptcgsem) { + if (nptcg_from == NPTCG_FROM_PAL && max_purges == 0) + BUG_ON(1 < nptcg); + else + BUG_ON(max_purges < nptcg); + return; + } + + if (nptcg_from == NPTCG_FROM_KERNEL_PARAMETER) { + kp_override = 1; + nptcg = max_purges; + goto resetsema; + } + if (kp_override) { + need_ptcg_sem = num_possible_cpus() > nptcg; + return; + } + + if (nptcg_from == NPTCG_FROM_PALO) { + palo_override = 1; + + /* In PALO max_purges == 0 really means it! */ + if (max_purges == 0) + panic("Whoa! Platform does not support global TLB purges.\n"); + nptcg = max_purges; + if (nptcg == PALO_MAX_TLB_PURGES) { + need_ptcg_sem = 0; + return; + } + goto resetsema; + } + if (palo_override) { + if (nptcg != PALO_MAX_TLB_PURGES) + need_ptcg_sem = (num_possible_cpus() > nptcg); + return; + } + + /* In PAL_VM_SUMMARY max_purges == 0 actually means 1 */ + if (max_purges == 0) max_purges = 1; + + if (firstcpu) { + nptcg = max_purges; + firstcpu = 0; + } + if (max_purges < nptcg) + nptcg = max_purges; + if (nptcg == PAL_MAX_PURGES) { + need_ptcg_sem = 0; + return; + } else + need_ptcg_sem = (num_possible_cpus() > nptcg); + +resetsema: + spinaphore_init(&ptcg_sem, max_purges); +} + +void +ia64_global_tlb_purge (struct mm_struct *mm, unsigned long start, + unsigned long end, unsigned long nbits) +{ + struct mm_struct *active_mm = current->active_mm; + + toolatetochangeptcgsem = 1; + + if (mm != active_mm) { + /* Restore region IDs for mm */ + if (mm && active_mm) { + activate_context(mm); + } else { + flush_tlb_all(); + return; + } + } + + if (need_ptcg_sem) + down_spin(&ptcg_sem); + + do { + /* + * Flush ALAT entries also. + */ + ia64_ptcga(start, (nbits << 2)); + ia64_srlz_i(); + start += (1UL << nbits); + } while (start < end); + + if (need_ptcg_sem) + up_spin(&ptcg_sem); + + if (mm != active_mm) { + activate_context(active_mm); + } +} + +void +local_flush_tlb_all (void) +{ + unsigned long i, j, flags, count0, count1, stride0, stride1, addr; + + addr = local_cpu_data->ptce_base; + count0 = local_cpu_data->ptce_count[0]; + count1 = local_cpu_data->ptce_count[1]; + stride0 = local_cpu_data->ptce_stride[0]; + stride1 = local_cpu_data->ptce_stride[1]; + + local_irq_save(flags); + for (i = 0; i < count0; ++i) { + for (j = 0; j < count1; ++j) { + ia64_ptce(addr); + addr += stride1; + } + addr += stride0; + } + local_irq_restore(flags); + ia64_srlz_i(); /* srlz.i implies srlz.d */ +} + +void +flush_tlb_range (struct vm_area_struct *vma, unsigned long start, + unsigned long end) +{ + struct mm_struct *mm = vma->vm_mm; + unsigned long size = end - start; + unsigned long nbits; + +#ifndef CONFIG_SMP + if (mm != current->active_mm) { + mm->context = 0; + return; + } +#endif + + nbits = ia64_fls(size + 0xfff); + while (unlikely (((1UL << nbits) & purge.mask) == 0) && + (nbits < purge.max_bits)) + ++nbits; + if (nbits > purge.max_bits) + nbits = purge.max_bits; + start &= ~((1UL << nbits) - 1); + + preempt_disable(); +#ifdef CONFIG_SMP + if (mm != current->active_mm || cpumask_weight(mm_cpumask(mm)) != 1) { + platform_global_tlb_purge(mm, start, end, nbits); + preempt_enable(); + return; + } +#endif + do { + ia64_ptcl(start, (nbits<<2)); + start += (1UL << nbits); + } while (start < end); + preempt_enable(); + ia64_srlz_i(); /* srlz.i implies srlz.d */ +} +EXPORT_SYMBOL(flush_tlb_range); + +void ia64_tlb_init(void) +{ + ia64_ptce_info_t uninitialized_var(ptce_info); /* GCC be quiet */ + u64 tr_pgbits; + long status; + pal_vm_info_1_u_t vm_info_1; + pal_vm_info_2_u_t vm_info_2; + int cpu = smp_processor_id(); + + if ((status = ia64_pal_vm_page_size(&tr_pgbits, &purge.mask)) != 0) { + printk(KERN_ERR "PAL_VM_PAGE_SIZE failed with status=%ld; " + "defaulting to architected purge page-sizes.\n", status); + purge.mask = 0x115557000UL; + } + purge.max_bits = ia64_fls(purge.mask); + + ia64_get_ptce(&ptce_info); + local_cpu_data->ptce_base = ptce_info.base; + local_cpu_data->ptce_count[0] = ptce_info.count[0]; + local_cpu_data->ptce_count[1] = ptce_info.count[1]; + local_cpu_data->ptce_stride[0] = ptce_info.stride[0]; + local_cpu_data->ptce_stride[1] = ptce_info.stride[1]; + + local_flush_tlb_all(); /* nuke left overs from bootstrapping... */ + status = ia64_pal_vm_summary(&vm_info_1, &vm_info_2); + + if (status) { + printk(KERN_ERR "ia64_pal_vm_summary=%ld\n", status); + per_cpu(ia64_tr_num, cpu) = 8; + return; + } + per_cpu(ia64_tr_num, cpu) = vm_info_1.pal_vm_info_1_s.max_itr_entry+1; + if (per_cpu(ia64_tr_num, cpu) > + (vm_info_1.pal_vm_info_1_s.max_dtr_entry+1)) + per_cpu(ia64_tr_num, cpu) = + vm_info_1.pal_vm_info_1_s.max_dtr_entry+1; + if (per_cpu(ia64_tr_num, cpu) > IA64_TR_ALLOC_MAX) { + static int justonce = 1; + per_cpu(ia64_tr_num, cpu) = IA64_TR_ALLOC_MAX; + if (justonce) { + justonce = 0; + printk(KERN_DEBUG "TR register number exceeds " + "IA64_TR_ALLOC_MAX!\n"); + } + } +} + +/* + * is_tr_overlap + * + * Check overlap with inserted TRs. + */ +static int is_tr_overlap(struct ia64_tr_entry *p, u64 va, u64 log_size) +{ + u64 tr_log_size; + u64 tr_end; + u64 va_rr = ia64_get_rr(va); + u64 va_rid = RR_TO_RID(va_rr); + u64 va_end = va + (1<<log_size) - 1; + + if (va_rid != RR_TO_RID(p->rr)) + return 0; + tr_log_size = (p->itir & 0xff) >> 2; + tr_end = p->ifa + (1<<tr_log_size) - 1; + + if (va > tr_end || p->ifa > va_end) + return 0; + return 1; + +} + +/* + * ia64_insert_tr in virtual mode. Allocate a TR slot + * + * target_mask : 0x1 : itr, 0x2 : dtr, 0x3 : idtr + * + * va : virtual address. + * pte : pte entries inserted. + * log_size: range to be covered. + * + * Return value: <0 : error No. + * + * >=0 : slot number allocated for TR. + * Must be called with preemption disabled. + */ +int ia64_itr_entry(u64 target_mask, u64 va, u64 pte, u64 log_size) +{ + int i, r; + unsigned long psr; + struct ia64_tr_entry *p; + int cpu = smp_processor_id(); + + if (!ia64_idtrs[cpu]) { + ia64_idtrs[cpu] = kmalloc_array(2 * IA64_TR_ALLOC_MAX, + sizeof(struct ia64_tr_entry), + GFP_KERNEL); + if (!ia64_idtrs[cpu]) + return -ENOMEM; + } + r = -EINVAL; + /*Check overlap with existing TR entries*/ + if (target_mask & 0x1) { + p = ia64_idtrs[cpu]; + for (i = IA64_TR_ALLOC_BASE; i <= per_cpu(ia64_tr_used, cpu); + i++, p++) { + if (p->pte & 0x1) + if (is_tr_overlap(p, va, log_size)) { + printk(KERN_DEBUG "Overlapped Entry" + "Inserted for TR Register!!\n"); + goto out; + } + } + } + if (target_mask & 0x2) { + p = ia64_idtrs[cpu] + IA64_TR_ALLOC_MAX; + for (i = IA64_TR_ALLOC_BASE; i <= per_cpu(ia64_tr_used, cpu); + i++, p++) { + if (p->pte & 0x1) + if (is_tr_overlap(p, va, log_size)) { + printk(KERN_DEBUG "Overlapped Entry" + "Inserted for TR Register!!\n"); + goto out; + } + } + } + + for (i = IA64_TR_ALLOC_BASE; i < per_cpu(ia64_tr_num, cpu); i++) { + switch (target_mask & 0x3) { + case 1: + if (!((ia64_idtrs[cpu] + i)->pte & 0x1)) + goto found; + continue; + case 2: + if (!((ia64_idtrs[cpu] + IA64_TR_ALLOC_MAX + i)->pte & 0x1)) + goto found; + continue; + case 3: + if (!((ia64_idtrs[cpu] + i)->pte & 0x1) && + !((ia64_idtrs[cpu] + IA64_TR_ALLOC_MAX + i)->pte & 0x1)) + goto found; + continue; + default: + r = -EINVAL; + goto out; + } + } +found: + if (i >= per_cpu(ia64_tr_num, cpu)) + return -EBUSY; + + /*Record tr info for mca hander use!*/ + if (i > per_cpu(ia64_tr_used, cpu)) + per_cpu(ia64_tr_used, cpu) = i; + + psr = ia64_clear_ic(); + if (target_mask & 0x1) { + ia64_itr(0x1, i, va, pte, log_size); + ia64_srlz_i(); + p = ia64_idtrs[cpu] + i; + p->ifa = va; + p->pte = pte; + p->itir = log_size << 2; + p->rr = ia64_get_rr(va); + } + if (target_mask & 0x2) { + ia64_itr(0x2, i, va, pte, log_size); + ia64_srlz_i(); + p = ia64_idtrs[cpu] + IA64_TR_ALLOC_MAX + i; + p->ifa = va; + p->pte = pte; + p->itir = log_size << 2; + p->rr = ia64_get_rr(va); + } + ia64_set_psr(psr); + r = i; +out: + return r; +} +EXPORT_SYMBOL_GPL(ia64_itr_entry); + +/* + * ia64_purge_tr + * + * target_mask: 0x1: purge itr, 0x2 : purge dtr, 0x3 purge idtr. + * slot: slot number to be freed. + * + * Must be called with preemption disabled. + */ +void ia64_ptr_entry(u64 target_mask, int slot) +{ + int cpu = smp_processor_id(); + int i; + struct ia64_tr_entry *p; + + if (slot < IA64_TR_ALLOC_BASE || slot >= per_cpu(ia64_tr_num, cpu)) + return; + + if (target_mask & 0x1) { + p = ia64_idtrs[cpu] + slot; + if ((p->pte&0x1) && is_tr_overlap(p, p->ifa, p->itir>>2)) { + p->pte = 0; + ia64_ptr(0x1, p->ifa, p->itir>>2); + ia64_srlz_i(); + } + } + + if (target_mask & 0x2) { + p = ia64_idtrs[cpu] + IA64_TR_ALLOC_MAX + slot; + if ((p->pte & 0x1) && is_tr_overlap(p, p->ifa, p->itir>>2)) { + p->pte = 0; + ia64_ptr(0x2, p->ifa, p->itir>>2); + ia64_srlz_i(); + } + } + + for (i = per_cpu(ia64_tr_used, cpu); i >= IA64_TR_ALLOC_BASE; i--) { + if (((ia64_idtrs[cpu] + i)->pte & 0x1) || + ((ia64_idtrs[cpu] + IA64_TR_ALLOC_MAX + i)->pte & 0x1)) + break; + } + per_cpu(ia64_tr_used, cpu) = i; +} +EXPORT_SYMBOL_GPL(ia64_ptr_entry); |